Answer:
Relatively recent research has shown that heart failure is a significant risk factor for kidney disease. When the heart is no longer pumping efficiently it becomes congested with blood, causing pressure to build up in the main vein connected to the kidneys and leading to congestion of blood in the kidneys, too.
Reference:
https://www.bhf.org.uk/informationsupport/heart-matters-magazine/medical/kidney-heart-link
